JP3451733B2 - Vehicle traction control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control device for performing engine traction control and brake traction control of a vehicle, and more particularly, to reduce the heat load on valves and to reduce the relay switch of the energizing circuit of a pump drive motor. It relates to a product improved to ensure durability.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the driving wheels from slipping due to excessive driving torque and deteriorating the running performance during acceleration of the vehicle, the slip amount of the driving wheels is detected and the slip value of the driving wheels is A traction control technique for a vehicle, which is configured to control an engine driving force or a braking force applied to wheels so as to obtain a target slip value (reduce the engine driving force or increase the braking force), is generally put into practical use.

In this type of vehicle traction control, a wheel speed sensor for detecting the wheel speed of each of the four wheels is provided, and the slip amount of the drive wheel is calculated from the drive wheel speed and the driven wheel speed. The target slip amount is set according to the speed and the road surface friction coefficient. The road surface friction coefficient is estimated from the driven wheel speed and its acceleration (JP-A-60-997).
No. 57). In order to suppress slip of the drive wheels,
As a technique for suppressing the engine driving force, retard of ignition timing and / or fuel cut, or adjustment of an intake amount through a sub-throttle valve in an intake passage is applied.

As a technique for controlling the braking force, it is general to operate a braking device for driving wheels. However, in view of durability of the braking device, the target slip amount of the brake traction control is set to the engine traction control. If the slip amount is small, the engine driving force is reduced by the engine traction control.If the slip amount is large, the engine driving force is reduced and the braking force is reduced by the brake traction control. A traction control technique for increasing the power is also proposed (see Japanese Patent Laid-Open No. 63-166649).

As an example of a hydraulic system of a vehicle braking system to which the brake traction control is applied, a branched hydraulic passage that branches from a hydraulic pressure supply source and extends to a wheel cylinder of a brake mechanism for left and right driving wheels, and these branched passages. Pressure boosting valve and pressure reducing valve connected to each of the hydraulic pressure passages, a cut valve provided in the main hydraulic pressure passage leading from the master cylinder to both branch hydraulic pressure passages, and a pressure increasing valve connected to the main hydraulic pressure passage. A cylinder, a pump that supplies hydraulic pressure to the pressure increasing cylinder, a control valve and the like that are provided in the return hydraulic pressure passage from the pressure increasing cylinder are provided, and by controlling these pressure increasing valve and pressure reducing valve, the left and right There is also one configured to control the brake fluid pressure of the wheel cylinder.

The pressure-increasing valve and the pressure-reducing valve are duty solenoid valves, and the cut valve and the control valve are electromagnetic opening / closing valves. , Are closed by energizing each solenoid coil.

Here, in Japanese Patent Laid-Open No. 63-17158, the cumulative value of the values corresponding to the hydraulic pressure increase / decrease operation of the control valve of the brake hydraulic system for brake traction control is determined during execution of the brake traction control. A slip control device is described in which, when the value reaches a value, it is determined that the brake fluid pressure has dropped to zero pressure, and the brake fluid pressure system is switched to a normal brake fluid pressure system.

[0008]

In the traction control device for performing the engine traction control and the brake traction control, it is not necessary to operate the brake device when only the engine traction control is executed. The pump driving motor of the power source is stopped, the cut valve and the control valve are closed, and the energization of the solenoid is also stopped in order to reduce the thermal load on these valves.

However, when the brake traction control is stopped in response to a decrease in the slip of the driving wheels during traveling on a low friction road, the slip amount increases again and the brake traction control execution state is repeated again. However, in this case, the pump drive motor is ON and OF
Since it is frequently repeated F and ON, the durability of the relay switch of the motor drive circuit is reduced and the motor is turned ON and OF.
There is a problem that the vibration and the vibration sound associated with the F switching become worse. Further, since it takes 100 to 200 ms from the time when the pump driving motor is turned on until the brake fluid pressure is generated, there is a problem that the responsiveness when restarting the brake traction control is deteriorated.

Further, as described in JP-A-63-17158, control valves (pressure increasing valve and pressure reducing valve)
When estimating the brake fluid pressure from the cumulative value of the pressure increase / decrease time of, during 100 to 200 ms after the start of rotation of the motor,
Since the brake fluid pressure is not substantially generated, there is also a problem that the fluid pressure estimation accuracy is lowered by simply estimating the brake fluid pressure from the cumulative value of the pressure increasing / decreasing time of the control valve. An object of the present invention is to provide a traction control device for a vehicle that can reduce the thermal load on valves and ensure the durability of a relay switch of a drive circuit of a pump drive motor.

[0011]

According to a first aspect of the present invention, there is provided a vehicle traction control device for controlling engine traction so that a slip amount of a drive wheel becomes a first target slip amount in order to suppress a slip of the drive wheel with respect to a road surface. A traction control device for a vehicle, comprising: an engine traction control means for performing a traction control; and a brake traction control means for performing a brake traction control so that a slip amount of a drive wheel becomes a second target slip amount higher than a first target slip amount. , Left and right drive wheel braking device
Pump for supplying brake fluid pressure to the
And a road surface friction detecting means for detecting the friction coefficient of the road surface,
Hydraulic pressure detection means for detecting the brake hydraulic pressure of the brake device for the left and right drive wheels respectively, and the pump drive when the brake hydraulic pressure detected by the hydraulic pressure detection means decreases to a low pressure set value for both the left and right wheels. Hydraulic pressure generation stopping means for stopping the brake hydraulic pressure generation operation by the pump for the motor, and determining whether or not the engine traction control is being executed
A judging means for, left in e emissions Gin traction control execution
When the brake fluid pressure on the right drive wheel has dropped to the set value
To come, with respect to the fluid pressure generating stop means, on the basis of the road surface friction coefficient detected by the road surface friction detecting means, a brake fluid pressure generating operation stop time, when a low road surface friction coefficient, as compared to when a higher It is provided with a means for delaying the discontinuation time.

[0012] In this case, the brake system of the drive wheel, before
A branch hydraulic passage extending from the pump to the wheel cylinders of the left and right drive wheels, a pressure increasing valve and a pressure reducing valve connected to each of these branch hydraulic passages, and a main connecting the master cylinder to both branch hydraulic passages. Hydraulic pressure passage, cut valve provided in main hydraulic pressure passage, booster cylinder connected to main hydraulic pressure passage, pump for supplying hydraulic pressure to booster cylinder, return hydraulic pressure from booster cylinder It may be configured to include a control valve provided in the passage (claim 2 dependent on claim 1).

The hydraulic pressure detecting means detects each brake hydraulic pressure based on a value obtained by subtracting the pressure reduction accumulated time of the pressure reducing valve from the pressure accumulated accumulated time of the pressure increasing valve connected to each branch hydraulic pressure passage. (Claim 3 dependent on Claim 2). Said hydraulic sensing means, between pre Kipo pump rotation start of the drive motor for a predetermined time, the dependent claims both brake fluid pressure to the configuration may be (claim 3 to estimate the Rei圧4).

[0014]

In the vehicle traction control device according to the present invention, the engine traction control means and the brake traction control means are provided, and the road surface friction detecting means detects the friction coefficient of the road surface. The hydraulic pressure detecting means detects the brake hydraulic pressures of the brake devices for the left and right drive wheels, respectively. When the detected brake fluid pressure drops to the low pressure set value for both the left and right wheels, the hydraulic pressure generation stopping means applies brake fluid to the brake devices for the left and right drive wheels.
Wherein the pump driving motor of the pump for supplying the pressure
The brake fluid pressure generation operation by the pump is stopped, and the stop timing delay means is set to the left and right during engine traction control execution.
When the brake fluid pressure on the drive wheels of
In addition , the brake fluid pressure generation operation suspension timing is delayed with respect to the hydraulic pressure generation stopping means based on the detected road surface friction coefficient when the road surface friction coefficient is low compared to when it is high.

As described above, by means of the hydraulic pressure generation stopping means,
When the brake fluid pressure drops to the low pressure setting value for both the left and right wheels, the brake fluid pressure generation operation is stopped, so the electric power for brake hydraulic pressure generation is saved and the thermal load on the electromagnetic valves of the brake system is reduced. Can be reduced. Moreover, the stop timing delay means delays the brake hydraulic pressure generating operation stop timing when the road friction coefficient is low compared to when it is high, so that the responsiveness when the brake traction control is restarted can be increased, Turning on the pump drive motor,
By reducing the frequency of OFF, the durability of the relay switch of the motor drive circuit can be ensured, and the vibration and vibration noise accompanying the ON / OFF switching of the motor can be reduced.

In a traction control device for a vehicle according to a second aspect of the present invention, the braking device for the driving wheels is the pump.
A branch hydraulic passage extending from the flop to the wheel cylinders of the left and right driving wheels, and the pressure increasing valve and pressure reducing valve connected to each of these branch fluid pressure passage, a main fluid pressure for connecting the master cylinder to both branch liquid pressure passage A passage, a cut valve provided in the main hydraulic pressure passage, a pressure increasing cylinder connected to the main hydraulic pressure passage, a pump for supplying hydraulic pressure to the pressure increasing cylinder, and a return hydraulic pressure passage from the pressure increasing cylinder. It is equipped with a control valve provided, and when the brake traction control is executed, the cut valve and the control valve are closed, hydraulic pressure is supplied from the pump to both wheel cylinders, and the brake hydraulic pressure is increased by the pressure boosting cylinder.
The brake fluid pressure is controlled via the pressure increasing valve and the pressure reducing valve.

According to another aspect of the vehicle traction control device of the present invention, the hydraulic pressure detecting means has a value obtained by subtracting the depressurizing cumulative time of the depressurizing valve from the cumulative pressure increasing time of the pressure boosting valve connected to each branch hydraulic passage. Based on this, each brake fluid pressure is detected. Therefore, the brake fluid pressure can be detected through the arithmetic processing without providing a device such as a sensor for detecting the brake fluid pressure.

[0018] In the traction control apparatus for a vehicle according to claim 4, hydraulic sensing means before Kipo amplifier between start of rotation of the drive motor for a predetermined time in order to estimate both the brake fluid pressure and Rei圧, The accuracy of estimating the brake fluid pressure can be improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example of applying the present invention to a traction control device for a rear-wheel drive type vehicle. As shown in FIG. 1, in this vehicle,
Front wheels 1 and 2 driven wheels of the right and left, left and right rear wheels 3 and 4 are driving wheels, the driving torque of the engine 5 of a V-type 6-cylinder mounted on the front of the vehicle body, the torque converter and a planetary gear type From the automatic transmission 6 including the transmission gear mechanism to the propeller shaft 7,
It is configured to be transmitted to the left and right rear wheels 3 and 4 via the differential device 8 and the left and right rear wheel drive shafts 9 and 10.

On the upper side between the left and right banks of the engine 5,
A surge tank 12 connected to the intake pipe 11 is provided,
Each of the six branch intake pipes 13 extends from the side portion of the surge tank 12 and is connected to the intake port of the bank on the opposite side,
An injector 14 for injecting fuel into the branch intake pipe 13 or an intake port is attached to each branch intake pipe 13, and the intake pipe 11 has a main throttle valve 16 linked to an accelerator pedal 15 and an upstream side thereof. A sub-throttle valve 17 is provided, an actuator 18 for rotatably driving the sub-throttle valve 17 is provided, and a distributor that outputs an ignition signal to six ignition plugs in a predetermined order and at a predetermined timing. 19 is also provided.

The left and right front wheels 1, 2 and the rear wheels 3, 4 receive disks 21a to 24a that rotate integrally with the wheels and brake hydraulic pressure and are supplied to these disks 21a to 24a.
Brake devices 21 to 24, which are composed of calipers 21b to 24b for braking the rotation of the brakes, are provided respectively, and a braking system 20 that operates these brake devices 21 to 24 is provided.

The braking system 20 will be described with reference to FIG. As shown in FIG. 2, the braking system 20 basically includes a tandem master cylinder 26 operated by a brake pedal 25, a wheel cylinder 23c of a caliper 23b of a left rear wheel 3, and a caliper of a right rear wheel 4. 24b of the wheel cylinders 24c, the main oil pressure passage 27 extending from the master cylinder 2 6, the wheel cylinder 23 is branched at a branch point a from the main oil pressure passage 27
branch hydraulic passages 31, 32 respectively connected to c and 24c,
The wheel cylinder 21c of the caliper 21b of the left front wheel 1,
The wheel cylinder 22c of the caliper 22b of the right front wheel 2,
A main hydraulic passage 28 extending from the master cylinder 26,
Branch hydraulic passages 51 and 52 are provided which branch from the main hydraulic passage 28 at a branch point B and are connected to the wheel cylinders 21c and 22c, respectively.

Further, the braking system 20 includes a rear wheel ABS hydraulic system 30 and a front wheel ABS hydraulic system 50 for anti-skid brake control, and a rear wheel TCS hydraulic system 70 for brake traction control. These hydraulic systems 3
A pump driving motor 29 shared by 0, 50 and 70 is provided.

Next, the rear wheel ABS hydraulic system 30 will be described. A pressure increasing valve 33 is provided in the branch hydraulic passage 31, and the branch hydraulic passage 31 is provided downstream of the pressure increasing valve 33.
The return oil passage 35 connected to is connected to a reservoir 36, and the return oil passage 35 is provided with a pressure reducing valve 34. Bypass oil passage 3 that bypasses the booster valve 33
7 is a check valve 3 which allows a hydraulic flow in the returning direction.
8 are provided.

Similarly, a pressure increasing valve 39 is provided in the branch hydraulic passage 32, and a return oil passage 41 connected to the branch hydraulic passage 32 on the downstream side of the pressure increasing valve 39 is connected to the reservoir 36. The return oil passage 41 is provided with a pressure reducing valve 40. The bypass oil passage 42 that bypasses the pressure boosting valve 39 is provided with a check valve 43 that allows a hydraulic pressure to flow in the return direction.

Hydraulic pressure supply passage 4 provided with a hydraulic pump 44
5 extends from the reservoir 36, and the main hydraulic passage 27
The check valve 46, the hydraulic pump 44, the check valve 47, the throttle valve 48, and the check valve 49 are sequentially connected to the hydraulic supply path 45 from the reservoir 36 side. It is driven by the motor 29. Pressure increasing valves 33, 39 and pressure reducing valve 3
Reference numerals 4 and 40 are duty solenoid valves capable of opening and closing the oil passage and finely adjusting the degree of valve opening.

Next, the front wheel ABS hydraulic system 50 will be described. A pressure increasing valve 53 is provided in the branch hydraulic passage 51, and the branch hydraulic passage 51 is provided downstream of the pressure increasing valve 53.
The return oil passage 55 connected to is connected to the reservoir 56, and the return oil passage 55 is provided with a pressure reducing valve 54. Bypass oil passage 5 that bypasses the booster valve 53
7 is a check valve 5 which allows a hydraulic flow in the returning direction.
8 are provided. Similarly to this, the branch hydraulic passage 52
Is provided with a pressure increasing valve 59, and a return oil passage 61 connected to the branch hydraulic passage 52 on the downstream side of the pressure increasing valve 59.
Is connected to a reservoir 56, and in this return oil passage 61,
A pressure reducing valve 60 is provided. The bypass oil passage 62 that bypasses the pressure increasing valve 59 is provided with a check valve 63 that allows the flow of hydraulic pressure in the returning direction.

Hydraulic pressure supply path 6 provided with a hydraulic pump 64
5 extends from the reservoir 56 and is connected to the main hydraulic passage 28.
A check valve 66, a hydraulic pump 64, a check valve 67, a throttle valve 68, and a check valve 69 are sequentially connected to the hydraulic supply path 65 from the reservoir 56 side. The hydraulic pump 64 is driven by the motor 29. The pressure increasing valves 53 and 59 and the pressure reducing valves 54 and 60 are duty solenoid valves capable of opening and closing the oil passage and finely adjusting the degree of valve opening.

Next, the rear wheel TCS hydraulic system 70 will be described. The main hydraulic passage 27 is provided with a cut valve 71 capable of opening and closing the passage, and the bypass oil passage 72 bypassing the cut valve 71 is provided with a check valve 73 for allowing a hydraulic pressure to flow in the downstream direction. Also, a bypass oil passage 74 that bypasses the cut valve 71
Is provided with a check valve 75 that allows a hydraulic pressure flow in the upstream direction when a hydraulic pressure higher than the brake hydraulic pressure generated during execution of the brake traction control is applied.

Further, a pressure increasing cylinder 76 is provided for increasing the hydraulic pressure in the main hydraulic pressure passage 27 when the brake traction control is executed. This pressure boosting cylinder 7
The discharge port 77 of No. 6 is connected to the main hydraulic passage 27 via the pressure increasing oil passage 78, and the input oil chamber 79 of the pressure increasing cylinder 76 is connected.
Is connected to a reservoir 82 by a hydraulic input path 81 having a hydraulic pump 80. The hydraulic input path 81 includes a check valve 83 and a hydraulic pump 8 in order from the reservoir 82 side.
0, a check valve 84 is provided, and the hydraulic pump 80 is driven by the pump driving motor 29.

The return oil passage 85 connected to the input oil chamber 79 of the pressure increasing cylinder 76 is connected to the reservoir 82, and the return oil passage 85 is provided with a control valve 86 capable of opening and closing the oil passage. There is. In addition, reference numeral 87 is a relief valve which is operated by relief at a predetermined high hydraulic pressure,
The cut valve 71 and the control valve 86 are open / close solenoid valves. The pressure increasing cylinder 76
The piston 88 is urged toward the input oil chamber 79 by the return spring 89, and when the oil pressure is supplied to the input oil chamber 79, the piston 88 moves in the discharge direction against the return spring 89. The hydraulic pressure is discharged to the hydraulic passage 27.

As shown in FIG. 1, left and right front and rear wheels 1
Wheel speed sensor 9 for detecting wheel speeds V1 to V4
1a to 94a, a steering angle sensor 93 that detects the steering angle of the steering wheel 92, a brake switch 94 that is turned on when the brake pedal 25 is operated, and an engine speed sensor 9
5, an accelerator sensor 96 that detects the amount of depression of the accelerator pedal 15, a throttle sensor 97 that detects the opening of the main throttle valve 16, a sensor such as a mode switch 98 that sets a running mode (sport mode, normal mode, safety mode) Kind is provided. The wheel speed sensors 91a to 94a are connected to the brake discs 21a to 24a.
The electromagnetic pickup is used to detect a plurality of detection portions formed in a or in the vicinity thereof.

Further, in response to detection signals from the sensors and switches, engine traction control for the engine 5, anti-skid brake control for the brake devices 21-24, and brake traction control for the brake devices 23, 24 are executed. A slip control unit 90 for controlling the engine 5 is provided, and an engine control unit 110 for controlling the engine 5 and a transmission control unit 120 for controlling the automatic transmission 6 are also provided. However, the engine control unit 110 is supplied with various detection signals such as the vehicle speed, the opening degree of the main throttle valve, the engine speed, the intake air amount, the shift position of the shift lever, and the transmission control unit 120. Is the vehicle speed, the main throttle valve 1
Various detection signals such as the throttle opening degree of 6, the shift position of the shift lever, the oil temperature and hydraulic pressure of the transmission 6, and the like are supplied. In the following description, the traction control may be abbreviated as "TCS control" and the anti-skid brake control may be abbreviated as "ABS control".

A control signal for engine TCS control is supplied from the slip control unit 90 to the engine control unit 110, and the engine control unit 110 sends an auxiliary throttle through the actuator 18 based on the control signal for engine TCS control. Control valve 17. Further, from the slip control unit 90 to the braking system 20,
A control signal for brake TCS control and a control signal for ABS control are supplied. The slip control unit 90 includes a waveform shaping circuit that shapes the detection signals from the sensors and switches as necessary, and various detection signals as necessary.
It is composed of an A / D converter for conversion, an input / output interface, a microcomputer, a drive circuit for the valves and the motor 29, a plurality of timers, and the like. Control programs for various controls, tables, maps, etc. are stored in advance, and various work memories are provided in the RAM.

The engine TCS control will be briefly described. The slip amount of the drive wheels 3 and 4 is determined by the engine TC.
When it becomes larger than the target slip amount for S control,
The opening of the sub-throttle valve 17 is adjusted in the closing direction to reduce the driving force of the engine 5 and suppress the slip of the drive wheels 3 and 4. The ABS control will be briefly described. Each wheel (driving wheel 3, 4 and driven wheel 1, mainly during braking).
When 2) is in the locked state, the motor 29 is actuated and the corresponding pressure reducing valves 34, 40, 54, 60 and the pressure increasing valves 33, 3 of the ABS hydraulic systems 30, 50 are activated.
A predetermined pattern of reducing, maintaining, and increasing the brake hydraulic pressure via 9, 53, 59 is repeated to control the slip amount to be equal to or less than the predetermined target slip amount for ABS control.

The brake TCS control will be briefly described. The slip amount of the drive wheels 3 and 4 depends on the brake TC.
When it becomes larger than the target slip amount for S control,
The motor 29 is driven, the cut valve 71 and the control valve 86 are closed, and the pressure increasing valves 33 and 39 are opened.
The pressure reducing valves 34 and 40 are closed to supply hydraulic pressure from the pressure increasing cylinder 76 to the wheel cylinders 23c and 24c to enhance the braking force, so that the slip amount of the drive wheels 3 and 4 becomes equal to or less than the target slip amount for brake TCS control. The brake hydraulic pressure is controlled so that However, in practice, the brake traction control is individually executed for both the wheel cylinders 23c and 24c.

Next, the traction control including the engine TCS control and the brake TCS control executed by the slip control unit 90 will be described with reference to the drawings starting from FIG. 3. First, an outline of the traction control will be described. I will explain. The target slip amount of the drive wheels 3 and 4 (target slip amount for throttle control, target slip amount for brake control) is set according to the running state of the vehicle and the road friction state, and the slip amount of the drive wheels 3 and 4 is set. The auxiliary throttle valve 17 is controlled so that the slip amount is equal to or smaller than the throttle control target slip amount when the vehicle is accelerated, etc., and the slip amount is calculated by using the wheel speeds of the four wheels. The brake devices 23 and 24 are controlled via the pressure increasing valves 33 and 39 and the pressure reducing valves 34 and 40 so that the slip amount becomes equal to or less than the slip amount.

Next, the traction control routine will be described with reference to the flowcharts of FIG.
Incidentally, reference numeral Si (i = 1, 2, 3 ...) In the drawing indicates each step, and the main routine shown in FIG. 3 is repeatedly executed every predetermined minute time (for example, 8 ms).

In FIG. 3, when control is started by starting the engine, slip amount detection processing is executed (S
1) Next, a target slip amount setting process is executed (S
2) Next, a slip determination process is executed (S3), and then a target control amount calculation process for throttle control is executed (S).
4) Next, a target control amount calculation process for brake control is executed (S5), and then a slip flag F for throttle control is applied.
A control signal for throttle control is output to the engine control unit 110 under the condition of e = 1 (S6), and then, for the left rear wheel brake control under the condition of the brake control slip flag Fb1 = 1 of the left rear wheel 3. A control signal is output, and a brake control slip flag Fb2 = 1 for the right rear wheel 4 is output.
Under the condition, the control signal for controlling the right rear wheel brake is output (S7), and then the process returns.

Next, each of the subroutines S1 to S5 will be described in order. Slip amount detection process ... See FIG. 4. When this slip amount detection process subroutine is started, first, wheel speeds V1 to V1 of the left and right front wheels 1 and 2 and rear wheels 3 and 4 from the wheel speed sensors 91a to 94a. V4 is read (S10), then the vehicle speed V, which is the vehicle body speed, is calculated as the average value of the left and right driven wheel speeds V1 and V2, and the maximum drive wheel speed Vm is calculated from the left and right drive wheel speeds V3 and V4. It is calculated as the maximum value (S11). Next, in S12, the slip amount Se for throttle control, the slip amount Sb1 for left rear wheel brake control, and the slip amount Sb2 for right rear wheel brake control are calculated by the equations shown in the drawing, and the data of these slip amounts are stored in the work memory. It is stored while updating to.

Target slip amount setting process ... See FIG. 5. When the subroutine of this target slip amount setting process is started, various signals (road surface friction coefficient μ,
The vehicle speed V, the accelerator depression amount, the detected steering angle θ, the mode signal from the mode switch 98, the brake switch signal from the brake switch 94, etc.) are read (S20).

Here, the road surface friction coefficient μ is calculated by an interrupt processing routine (not shown) based on the vehicle speed V and its acceleration Vg as follows, and is updated every moment.
To calculate the road surface friction coefficient μ, a timer of 100 ms count and a timer of 500 ms count are used, and the vehicle speed V changes every 100 ms for 100 ms from the start of slip control until 500 ms when the vehicle body acceleration Vg does not become sufficiently large. Then, the vehicle body acceleration Vg is obtained from the following equation (1), and the vehicle body acceleration Vg becomes sufficiently large.
After 0 ms, the vehicle speed V for 500 ms every 100 ms
Then, the vehicle body acceleration Vg is obtained from the following equation (2). Note that V (i) is currently 100 as V (i-100).
ms before, V (i-500) is each vehicle speed before 500 ms, and K1 and K2 are predetermined constants. Note that ms is m
It is sec.

Vg = K1 × [V (i) -V (i-100)] (1) Vg = K2 × [V (i) -V (i-500)] (2) The road surface friction coefficient μ is The vehicle speed V obtained as described above,
It is calculated by three-dimensional complementation from the μ table shown in Table 1 using the vehicle body acceleration Vg, and stored in the work memory while being updated.

[0044]

[Table 1]

Next, in S21, the map M0 of FIG.
By applying the road surface friction coefficient μ to the throttle control target slip amount basic value SETo and the brake control target slip amount basic value SBTo. As shown in the map M0, the basic value SETo is set smaller than the basic value SBTo because the engine traction control suppresses the slip when the slip amount is small and the engine traction is large when the slip amount is large. This is to prevent the load on the brake devices 23 and 24 from increasing by suppressing the slip by the control and the brake traction control.

Next, in S22, the basic value SETo
And the basic value SBTo are calculated as coefficients k1 to k4 for correcting the basic value SBTo according to the traveling state of the vehicle. That is, the vehicle speed V is applied to the map M1 of FIG. 10 to calculate the coefficient k1.
The coefficient k2 is calculated by applying the accelerator depression amount to the map M2 of FIG. 1, the coefficient k3 is calculated by applying the steering angle θ to the map M3 of FIG. 12, and the coefficient k4 is calculated from the map M4 of FIG. 13 and the mode signal. Is calculated. Next, in S23, the coefficient KD obtained by multiplying the above-mentioned coefficients k1 to k4 is calculated, and then in S24, the target slip amount SET for throttle control is set.
Is calculated as SET = basic value SETo × KD, and the target slip amount SBT for brake control is SBT = basic value SBTo ×
It is calculated as KD and these are stored in the work memory.

Slip determination process: see FIG. 6. When the slip determination process is started, various signals (slip amounts Se, Sb1, Sb2, target slip amount SET, SBT data, brake switch signal, etc.) are read. (S3
0) and then, in S31 to S34, a slip flag Fe for identifying the necessity of engine traction control,
A slip flag Fb1 for identifying the necessity of brake traction control for the brake device 23 of the left rear wheel 3 and a slip flag Fb2 for identifying the necessity of brake traction control for the brake device 24 of the right rear wheel 4 are set.

In S31, if the slip amount Se> the target slip amount SET, the flag Fe is set to 1, and the state of the slip amount Se ≦ the target slip amount SET continues for a predetermined time (for example, 1500 ms). , The flag Fe is reset to 0. Incidentally, the continuation of the predetermined time is actually judged through the timer and the timer flag. Next, in S32, if the slip amount Sb1> the target slip amount SBT, the flag Fb1
Is set to 1 and slip amount Sb1 ≦ target slip amount S
In the case of BT, the flag Fb1 is reset to 0, and
Similarly, the flag Fb2 is set to 1 when the slip amount Sb2> the target slip amount SBT, and the flag Fb2 is reset to 0 when the slip amount Sb2 ≦ the target slip amount SBT. Next, it is determined whether or not the brake switch 94 is ON. When it is ON, the flags Fb1 and Fb2 are reset to 0, and when it is OFF, the flag Fe,
Fb1 and Fb2 are held unchanged.

Target control amount calculation process for throttle control
-Refer to FIG. 7. When this calculation process is started, various signals (slip amount S
e, the target slip amount SET, the slip amount deviation EN (i-1) of the slip amount Se from the target slip amount SET, the engine speed Ne, the throttle opening TVO of the main throttle valve 16,
The final target control amount FTetg (i-1), slip flag Fe, vehicle speed V, and other data) are read (S40). However, the subscript (i-1) indicates the previous value and the subscript (i) indicates the current value.

Next, in S41, the slip amount deviation E
N and the current deviation EN (i) is calculated as the difference between the slip amount Se and the target slip amount SET, and the slip amount deviation change rate DEN is the deviation change rate DEN (i) at this time. It is calculated as the difference between the deviation EN (i) and the previous deviation EN (i-1). Next, in S42, the deviation EN (i) and deviation change rate DEN (i) of this time are applied to Table 2, and the basic control amount basic value T
eo is calculated, and the basic control amount basic value Teo is shown in Table 3.
Then, the basic control amount basic value Teo is digitized.

[0051]

[Table 2]

[Table 3]

Table 2 shows the engine traction control.
In the table, ZO indicates holding of the opening of the auxiliary throttle valve 17, N indicates closing of the auxiliary throttle valve 17, P indicates opening of the auxiliary throttle valve 17, and subscripts S, M, B.
Indicates the magnitude of the control amount, and S is “small control amount”,
M indicates "medium control amount" and B indicates "large control amount". The table in Table 3 is a numerical representation of the controlled variable in the table in Table 2, and the numerical value in Table 3 is the speed (% / s) for opening and closing the sub throttle valve 17.

Next, in order to correct the control amount according to the operating state of the engine, in S43, the engine speed Ne and the throttle opening TVO are applied to Table 4, and the correction coefficient K is applied.
e is calculated, and the basic control amount basic value Teo × Ke is set as the basic control amount Te (i) of this time.

[0054]

[Table 4]

Next, at S44, the final target control amount FTegt (i) of this time is set to a value obtained by adding the basic control amount Te (i) of this time to the last final target control amount FTegt (i-1) of the previous time. It Next, in S45, the previous slip flag Fe (i-1)
= 0, and whether or not the slip flag Fe (i) = 1 this time,
In other words, it is determined whether or not a series of engine traction control execution states have been entered this time, and if the determination is Yes,
In S46, the vehicle speed V and the road surface friction coefficient μ are applied to the map M5 of FIG. 14 to calculate the initial closing motion amount SM of the sub-throttle valve 17, and the final target control amount FTe of this time.
tg (i) is set to γ × SM. It should be noted that γ is a predetermined positive constant. If the determination in S45 is No,
S46 is skipped.

Target control amount calculation process for brake control ...
When the target control amount calculation process is started, various signals (slip amounts Sb1 and Sb2, target slip amount SBT, and slip amounts Sb1 and Sb2 of the slip amount deviation ENb1 (i-1 ), ENb2 (i-1), final target control amount FTb
Data such as tg1 (i-1) and FTbtg2 (i-1)) are read (S50). The subscript "1" indicates a pressure increasing valve and a pressure reducing valve for the brake device 23 of the left rear wheel 3, and the subscript "2".
Shows a pressure increasing valve and a pressure reducing valve for the brake device 24 of the right rear wheel 4.

Next, in S51, the slip amount deviation E
N is the deviations ENb1 (i) and ENb2 (i) of this time, and the slip amount deviation change rate DEN is the deviation change rate DENb1 (i) of this time.
, DENb2 (i) are calculated in the same manner as described above according to the calculation formula shown. Next, in S52, the current slip amount deviation ENb1 (i) and the current slip amount deviation change rate DENb1
(i) is applied to the table in Table 2 to calculate the basic value Tb1 (i) of the present basic control amount, and the slip amount deviation ENB2 (i) of this time and the slip amount deviation change rate DENb2 ( i)
Is applied to the table of Table 2 to calculate the basic value Tb2 (i) of the present basic control amount. Next, the basic control amount basic value T
b1 (i) and Tb2 (i) are applied to the table of Table 5, respectively, and these are digitized (S53).

[0058]

[Table 5]

The numerical values excluding the positive and negative signs in Table 5 are the duty ratios (%) of the duty solenoids of the pressure increasing valves 33, 39 and the pressure reducing valves 43, 40. This duty ratio is used when increasing the pressure. The duty ratios of 33 and 39 and the duty ratios of the pressure reducing valves 43 and 40 at the time of pressure reduction are shown. The pressure reducing valves 43 and 40 are fully closed (duty ratio = 0) when the pressure is increased, and the pressure increasing valves 33 and 39 are fully closed (duty ratio = 0) when the pressure is reduced. Next, in S54, the final target control amount FTbtg for this time
1 (i) and FTbtg2 (i) are the basic control amount basic value Tb1 (i) of this time, as compared with the final target control amount FTbtg1 (i-1), FTbtg2 (i-1) of the last time, as shown in the illustrated arithmetic expression. ) And Tb2 (i) are added together.

When the final target control amount FTetg (i) for engine traction control and the final target control amounts FTbtg1 (i), FTbtg2 (i) for brake traction control are calculated as described above, S6 of the main routine is calculated. , The final target control amount FTetg is set on condition that the slip flag Fe = 1.
A control signal corresponding to (i) is sent to the engine control unit 110.
To the slip flag Fb1 in S7.
= 1, the control signal corresponding to the final target control amount FTbtg1 (i) is output to the pressure increasing valve 33 and the pressure reducing valve 34 for the brake device 23 for the left rear wheel 3, and the slip flag Fb2 is output. = 1, the pressure increasing valve 39 and the pressure reducing valve 4 for the brake device 24 for the right rear wheel 4 are set.
With respect to 0, a control signal corresponding to the final target control amount FTbtg2 (i) is output.

Next, the brake oil pressure estimation process accompanying the main routine of FIG. 3 and executed in parallel with the main routine will be described with reference to FIG. This brake oil pressure estimation process is a process that is executed independently and simultaneously in parallel for the brake oil pressure of the wheel cylinder 23c of the left drive wheel 3 and the brake oil pressure of the wheel cylinder 24c of the right drive wheel 4. Is repeatedly executed every predetermined minute time (for example, a calculation cycle of 8 ms). The brake hydraulic pressure estimation process may be executed in the main routine of FIG.

Since the brake oil pressure estimating process for the brake oil pressure of the wheel cylinder 23c and the brake oil pressure estimating process for the brake oil pressure of the wheel cylinder 24c are the same, the former will be described as an example. When the brake hydraulic pressure estimation process is started, various signals (data such as a control signal to the drive circuit of the motor 29, a control signal to the pressure increasing valve 33, a control signal to the pressure reducing valve 34, and the previous brake hydraulic pressure) are transmitted. It is read (S60).

Next, in S61, it is determined whether or not the pump driving motor 29 has been switched from OFF to ON.
This determination may be made from the control signal to the drive circuit of the motor 29, or may be made based on whether or not at least one of the slip flags Fb1 and Fb2 is switched from "0" to "1". Then, when this determination is Yes, a count-up timer TM that counts up from, for example, 0 ms to 500 ms (the time count is TM)
Is reset and then started (S62), and then returns. If the determination in S61 is No, the motor 29 is turned on.
It is determined whether or not (S63), and if the determination is No,
In S74, the brake hydraulic pressure BPi is reset to 0 and then the process returns. Note that the reference numeral i (i = 1, 2) is a subscript, BP1 indicates the brake oil pressure of the wheel cylinder 23c, and BP2 indicates the brake oil pressure of the wheel cylinder 24c.

On the other hand, when the motor 29 is ON, the time TM measured by the timer TM is the predetermined time Δt (for example, Δt =
(100 to 200 ms) or less is determined (S64). That is, during the predetermined time Δt immediately after the start of the operation of the motor 29,
Even if the pump 47 rotates, the brake hydraulic pressure BPi is substantially equal to zero pressure. Therefore, when the determination in S64 is Yes,
The brake hydraulic pressure BPi is reset to 0 (S65), and then the process returns. When TM> Δt, S64 to S
In step S66, the control signal to the pressure increasing valve 33 is used to determine whether or not the pressure is increased (S66). When the pressure is being increased, the current pressure increasing time Tu is calculated as Tu = di × ΔT (S6).
7). Since di is the duty ratio of the control signal of the pressure increasing valve 33 and ΔT is 8 ms (calculation cycle), the pressure increasing time Tu is a time corresponding to the net pressure increasing time. next,
In S68 subsequent to S67, the current depressurization time Tw is 0.
After setting to, shifts to S73.

When the determination in S66 is No, it is determined from the control signal to the pressure reducing valve 34 whether or not the pressure is reduced (S69).
When the pressure is being reduced, the current pressure reduction time Tw is Tw =
It is calculated as di × ΔT (S70), then the current pressure increasing time Tu is set to 0 in S71, and then the process proceeds to S73. When the determination in S69 is No, S72
At this time, the pressure increase time Tu of this time is 0, and the pressure decrease time T of this time is
After setting w to 0, the process proceeds to S73. In S73, the current brake hydraulic pressure BPi is calculated by the following equation. BPi = BPi (previous value) + α × Tu−β × Tw The α and β are predetermined constants determined by the characteristics of the pressure increasing valve 33 and the pressure reducing valve 34, and thus the accumulated pressure increasing time and the cumulative pressure increasing time are accumulated. The brake hydraulic pressure BPi of this time is estimated using the difference from the depressurization time, and then the process returns. As described above, the brake hydraulic pressure is estimated moment by moment.
By setting the brake hydraulic pressure BPi to 0 during Δt immediately after the start of the operation of 9, it is possible to improve the accuracy of the brake hydraulic pressure estimation.

Next, with respect to the routine of the hydraulic system switching process accompanying the main routine of the traction control,
This will be described with reference to the flowchart of FIG. It should be noted that this routine is repeatedly executed at intervals of a predetermined minute time (for example, 8 ms) like the main routine, but this routine may be incorporated in the main routine.

When this hydraulic system switching process is started, various signals (data such as slip flags Fe, Fb1, Fb2, road friction coefficient μ, brake hydraulic pressures BP1 and BP2) are first displayed.
Is read (S80). Next, in S81, it is determined whether or not the brake TCS control is started. When at least one of the slip flags Fb1 and Fb2 is switched from "0" to "1", it is determined to be Yes, and in this case. , S82, the motor 29 is switched on, the control valve 86 and the cut valve 71 are closed, and then the process returns. If the determination in S81 is No, it is determined whether or not the motor 29 is in the ON state based on the control signal to the drive circuit of the motor 29 (S83). If the determination is No, the process returns, and if Yes, the wheel cylinder. It is determined whether or not the brake hydraulic pressure BP1 ≦ δ of 23c and the brake hydraulic pressure BP2 ≦ δ of the wheel cylinder 24c (S84). The above δ is a predetermined value which is substantially equal to zero, and the process returns from S84 until the brake hydraulic pressures BP1 and BP2 of both wheel cylinders 23c and 24c both decrease to the predetermined value δ.

When the pressure reduction is almost completed and the determination in S84 becomes Yes, it is determined in S85 based on the slip flag Fe whether or not the engine TCS control is being executed. If the determination is No, the process proceeds to S92. , S92, the motor 29 is turned off, the control valve 86 is opened, and the brake oil pressure is changed to the master cylinder 2
Control valve 8 to prevent backflow to 6
After the valve 6 is opened, the cut valve 71 is opened and then the process returns. In this way, the motor 29 and the valves 86 and 71
By switching and stopping the brake hydraulic pressure generation operation,
It is possible to reduce the heat load on the valves 86 and 71 and save the power consumption.

When the engine TCS control is being executed, the slips of the drive wheels 3 and 4 have not yet been sufficiently settled and there is a possibility that the brake TCS control will be restarted. It is provided. That is, S86
At, it is determined whether or not the road surface is a low friction road surface based on the road surface friction coefficient μ. If the road surface is not the low friction road surface, there is no possibility that the brake TCS control will be restarted, so the process proceeds to S92.

On the other hand, in the case of a low friction road surface, as compared with the case of a high friction road surface, whether or not the timer flag Ft is 0 in S87 in order to delay the switching timing to the motor 29 OFF. If the judgment is Yes, for example, a count-up timer Tm that counts up to 500 ms (its time is Tm)
Is reset and then started (S88), then the timer flag Ft is set to 1 in S89, and then the process returns. After setting the timer flag Ft, S87 to S90
And the measured time Tm is set time t0 in S90.
(For example, t0 = 300 ms), it is determined whether or not it is substantially equal, and if No, the process is repeated by returning to S
When the determination of 90 is Yes, the flag Ft is reset to 0 (S91) and then the process proceeds to S92.

As described above, when the engine TCS control is being executed and the road surface has a low friction, S92 is executed after delaying the set time t0, so that the brake TCS control can be restarted with good responsiveness when the brake TCS control is restarted. above,
Since the ON / OFF switching frequency of the motor 29 is also reduced, the durability of the relay switch of the motor drive circuit does not decrease, and the vibration and vibration noise accompanying the switching of the motor 29 are alleviated.

Next, an example of the drive circuit for the motor 29 and the valves 71 and 86 will be supplementarily described with reference to FIG.
The motor 29 is connected via 9a, one end of the relay coil of the relay switch 29a is connected to the power supply battery 100, and the other end of the relay coil is grounded via the transistor 29b. Cut valve 7
The solenoid 71a of No. 1 is connected to the power battery 100 via the transistor 71b, and the solenoid 86a of the control valve 86 is connected to the power battery 100 via the transistor 86b. The transistors 29b, 71b, 86b are connected to and controlled by the slip control unit 90.

Next, the operation of the traction control described above will be described. As shown in the time chart of FIG. 18, until time t1, the slip amount of the drive wheels 3 and 4 is small, the engine TCS control is not in the execution state, and the sub throttle valve 17 is in the fully open state. The amount of depression of the accelerator pedal 15 increases, and at time t1, the slip amount Se
However, when the target slip amount SET is exceeded, the engine TCS control execution state is entered, at which time the opening degree of the sub-throttle valve 17 is closed by the initial closing motion amount SM all at once, and thereafter the slip amount Se is the target slip amount. The opening degree of the sub-throttle valve 17 is feedback-controlled so as to reach SET.

At time t2, the slip amounts Sb1 and Sb2
However, since it becomes larger than the target slip amount SBT, the brake TCS control execution state is entered, and control for increasing the brake hydraulic pressure of the brake devices 23, 24 of the drive wheels 3, 4 is started, and engine TCS control and brake TCS control are performed. Both are executed. After that, the left and right wheel cylinders 23c,
The brake hydraulic pressures of 24c are respectively controlled by the feedback control, and at time t3, the slip amounts Sb1 and Sb2 become equal to or less than the target slip amount SBT, so the brake hydraulic pressure is reduced to zero pressure.

Here, in the traction control of the present application, as described with reference to FIG. 15, in the brake hydraulic pressure estimation process, the predetermined time Δ immediately after the start of the operation of the motor 29.
Considering that the brake hydraulic pressure is not substantially generated during the period t, the brake hydraulic pressure BPi (i
Since (1, 2) is set to 0, the accuracy of brake hydraulic pressure estimation can be improved. Further, as described with reference to FIG. 16, when the brake hydraulic pressures BP1 and BP2 of the left and right wheel cylinders 23c and 24c both decrease to almost zero pressure, the motor 29 is turned off and the valves 86 and 71 are opened. , The heat load of the valves 86 and 71 can be reduced to ensure their durability, and the power consumption can be reduced.

Further, when the engine TCS control is being executed and the road is low friction, the motor 29 is turned off after a delay of the set time t0 as compared with the case of the high friction road.
In addition, since the valves 86 and 71 are opened, not only the brake TCS control can be restarted with good responsiveness, but also the ON / OFF switching frequency of the motor 29 is reduced to improve the durability of the relay switch of the motor drive circuit. It is possible to prevent the deterioration, and it is possible to reduce the vibration and the vibration noise accompanying the switching of the motor 29. The term "hydraulic pressure" in the above embodiments means the "hydraulic pressure" of general hydraulic fluid for brake devices.

Next, another embodiment in which the above embodiment is partially modified will be described. 1] In the table of Table 2, slip amount deviation EN and
The deviation change rate DEN is set as a parameter,
One of these may be set as a parameter. Further, instead of the table of Table 2, a table for engine traction control and a table for brake traction control may be separately provided.

2] As shown in FIG. 19, steps S100 to S105 may be added to the flowchart of FIG. That is, S100 next to S68, S71, and S72
, The brake oil pressure BPi is a predetermined value P1 (however, P
(1 is the maximum oil pressure of about 0.7 to 0.8). If the result is No, at S101, α
Is set to αo × 1.0 (where αo is a constant corresponding to α in the above embodiment), and the brake hydraulic pressure BPi is set to a predetermined value P.
When 1 or more, in S102, α is αo × 0.8
Set to. This is because the hydraulic pressure increase rate is high while the brake hydraulic pressure is low, and the hydraulic pressure increase rate decreases when the brake hydraulic pressure is high.

Next, in S103, the brake hydraulic pressure B
Pi is a predetermined value P2 (however, P2 is the maximum oil pressure of 0.8 to 0.9
It is determined whether or not the value is equal to or higher than the above. If the determination is Yes, β is set to βo × 3.0 (however, βo is set in S104).
Is a constant corresponding to β in the above embodiment), and S
If the determination in 103 is No, in S105, β
Is set to βo × 1.0, and S104 or S105 to S7
Move to 3. This is because the hydraulic pressure decrease rate is high while the brake hydraulic pressure is high, and the hydraulic pressure decrease rate is low when the brake hydraulic pressure is low, so that it is corrected.

3] The traction control itself shown in FIGS. 3 to 8 is not limited to that of the embodiment,
It is also possible to apply various existing traction controls, and the engine TCS control can also be applied to the engine TCS control performed through the combustion cut method and / or the ignition timing retard, and the rear wheel TCS in the above-described embodiment. The hydraulic system 70 is also only an example, and various existing hydraulic systems can be applied.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a traction control device for a vehicle according to an embodiment.

FIG. 2 is a configuration diagram of a hydraulic system of a braking system.

FIG. 3 is a flowchart of a main routine of traction control.

FIG. 4 is a flowchart of a subroutine of slip amount detection processing.

FIG. 5 is a flowchart of a subroutine of target slip amount setting processing.

FIG. 6 is a flowchart of a subroutine of slip determination processing.

FIG. 7 is a flowchart of a subroutine of target control amount calculation processing for throttle control.

FIG. 8 is a flowchart of a subroutine of target control amount calculation processing for brake control.

FIG. 9 is a diagram showing a map M0.

FIG. 10 is a diagram showing a map M1.

FIG. 11 is a diagram showing a map M2.

FIG. 12 is a diagram showing a map M3.

FIG. 13 is a chart showing a map M4.

FIG. 14 is a diagram showing a map M5.

FIG. 15 is a flowchart of a routine of brake hydraulic pressure estimation processing.

FIG. 16 is a flowchart of a hydraulic system switching process routine.

17 is an electric circuit diagram of a drive circuit for the motor 29 and valves 71, 86. FIG.

FIG. 18 is a time chart of wheel speed, throttle opening, brake hydraulic pressure, and the like.

FIG. 19 is a partial flowchart of a routine of a brake oil pressure estimation process according to a modification.

[Explanation of symbols]

1, 2 front wheels (driven wheels) 3,4 Rear wheels (driving wheels) 5 engine 20 braking system 23,24 Brake device 29 motor 33,39 Booster valve 34,40 Pressure reducing valve 70 TCS hydraulic system for rear wheels 71 cut valve 86 Control valve 90 Slip control unit 91a-94a Wheel speed sensor 110 engine control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoyuki Hirao 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Reference JP-A-5-229417 (JP, A) JP-A-5 -170087 (JP, A) JP 3-114968 (JP, A) JP 63-180553 (JP, A) JP 63-130454 (JP, A) JP 5-278595 (JP, A) ) JP-A 5-221301 (JP, A) JP-A 5-112159 (JP, A) JP-A-63-31869 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60T 8/32-8/96 B60K 41/20

Claims (4)

(57) [Claims] 1. An engine traction control means for performing engine traction control so that a slip amount of a drive wheel becomes a first target slip amount in order to suppress a slip of the drive wheel on a road surface, and a slip amount of a drive wheel is first. In a traction control device for a vehicle, which comprises a brake traction control means for performing a brake traction control so that a second target slip amount higher than the first target slip amount , a brake fluid pressure is supplied to the brake devices for the left and right driving wheels.
The pump and the pump driving motor, the road surface friction detecting means for detecting the friction coefficient of the road surface, the hydraulic pressure detecting means for detecting the brake hydraulic pressure of the braking device for the left and right driving wheels respectively, and the hydraulic pressure detecting means for detecting the hydraulic pressure. When the brake fluid pressure drops to the low pressure setting value for both the left and right wheels ,
Hydraulic pressure generation stopping means for stopping the brake hydraulic pressure generation operation by the pump for the motor, and determining whether or not the engine traction control is being executed
And determination means, the blur of the left and right drive wheels during et emissions Gin traction control execution
When rk in fluid pressure has dropped to the set value, to the fluid pressure generating stop means, on the basis of the road surface friction coefficient detected by the road surface friction detecting means, a brake fluid pressure generating operation stop period, the road surface friction A traction control device for a vehicle, comprising: a stop timing delay means for delaying when the coefficient is low compared to when the coefficient is high. 2. A braking device of the driving wheel, the Pont
A branch hydraulic passage extending from the flop to the wheel cylinders of the left and right driving wheels, and the pressure increasing valve and pressure reducing valve connected to each of these branch fluid pressure passage, a main fluid pressure for connecting the master cylinder to both branch liquid pressure passage A passage, a cut valve provided in the main hydraulic pressure passage, a pressure increasing cylinder connected to the main hydraulic pressure passage, a pump for supplying hydraulic pressure to the pressure increasing cylinder, and a return hydraulic pressure passage from the pressure increasing cylinder. The traction control device for a vehicle according to claim 1, further comprising a control valve provided. 3. The hydraulic pressure detection means detects each brake hydraulic pressure based on a value obtained by subtracting the pressure reduction accumulated time of the pressure reducing valve from the pressure accumulated accumulated time of the pressure increasing valve connected to each branch hydraulic pressure passage. It is constituted so that it may be constituted.
Vehicle traction control device described in. Wherein said fluid pressure sensing means, between pre Kipo pump rotation start of the drive motor for a predetermined time, the billing, characterized in that configured the two brake fluid pressure to estimate the Rei圧Item 3. A vehicle traction control device according to item 3.